This application relates to systems and methods for design of interactive interfaces for computer programs.
Computer programs are a series of instructions that direct the operation of a computer. They are written by computer programmers to achieve a desired purpose. The instructions, taken as a whole, may define a computer application such as a word processing system, an accounting system, an inventory system or an arcade game. Most programs require interaction with the user of the computer program. In the case of a word processing program, the user keys text, formats and prints documents. In the case of an accounting program, the user enters the desired debits and credits and appropriate documentation, posts and selects reports. The schemes used to prompt the computer user to input data and to output information generated by the computer program to the computer user are known as human/computer interfaces.
This application relates to systems and methods that facilitate the computer programmer's task of writing programs with human/computer interfaces that are readily understandable and easy to use.
More and more, human/computer interfaces (whatever the application) make use of certain devices such as menus, windows, scroll bars, graphical displays, in addition to the traditional and still essential keypad and keyboard. Especially popular are direct manipulation interfaces (DMI) which are human/computer interfaces that allow the user to command the computer by selecting and manipulating pictures (sometimes called icons), usually with a pointing device such as a mouse. (A mouse is simply an input device which, when moved over a surface, "drags" a mouse pointer over the computer display. Typically, a mouse has several buttons which when pressed, initiate an input relating the button pusher and the location of the mouse cursor upon the computer display. The pressing or releasing of a mouse button is often referred to as a "mouse event".) The pictures of a DMI are designed to behave somewhat like the objects they represent. The Apple Macintosh employs direct manipulation extensively and is widely considered one of the easiest computers to use for people who are not necessarily computer specialists. The advantages of direct manipulation are widely recognized.
Unfortunately, direct manipulation interfaces are difficult to construct and difficult to modify once they are constructed. The programmer needs to write programs to create the pictures, move the pictures around the screen, determine what pictures the mouse is pointing to, what the pictures on the screen represent, what to do when a picture is selected and so forth. Although some programming languages and tools provide commands for drawing geometric figures and ways of sensing the mouse events, these basic capabilities are only the beginnings of a direct manipulation interface. Traditional programming languages leave the programmer to construct more sophisticated objects, such as menus. This is time consuming and often leads to complex and idiosyncratic interfaces.
User interface management systems are known which are computer programs that provide a collection of interface elements such as menus and dialog boxes and often include interactive tools for building prototype interfaces. See, for example, "Software Frameworks" Byte December 1984, describing Apple Computers Toolkit/32; "Macapp: An Application Framework", Byte August 1986; and "Objects, Icons and Software-ICS", Byte August 1986.
If a user interface management system has an interactive interface itself, it may be possible to create entire application interfaces without programming. For some applications, a good user interface management system may be sufficient. However, it is not always clear what interface elements and interactive tools will be needed and the interface elements and tools may not be readily modified or modified at all to suit the specific application.
Current estimates indicate that interface design can consume 50 percent of the time on a large programming project. Interfaces produced are usually difficult to debug and modify. Even though carefully thought out, interfaces are likely to need to be redesigned when tried with real users.